10-hydroxy-11-dihydroprostaglandin analogs as selective ep4 agonists

ABSTRACT

A compound comprising  
                 
or a pharmaceutically acceptable salt or a prodrug thereof, wherein the dashed line represents the presence or absence of a double bond; J is C═O or CHOH; 
     A is —(CH 2 ) 6 -, or cis —CH 2 CH═CH—(CH 2 ) 3 -, wherein 1 or 2 carbons may be substituted with S or O;    B is CO 2 H, or CO 2 R, CONR 2 , CONHCH 2 CH 2 OH, CON(CH 2 CH 2 OH) 2 , CH 2 OR, P(O)(OR) 2 , CONRSO 2 R, SONR 2 , or  
                 
 
R is H, C 1-6  alkyl; 
   D is —(CH 2 ) n -, —X(CH 2 ) n , or —(CH 2 ) n X-, wherein n is from 0 to 3 and X is S or O; and E is an aromatic or heteroaromatic moiety having from 0 to 4 substituents, said substituents each comprising from 1 to 6 non-hydrogen atoms is disclosed herein. Methods, compositions, and medicaments related thereto, as well as experimental results showing prostaglandin EP4 selective agonist activity for certain compounds disclosed herein, are also disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.10/821,705, which was filed on Apr. 9, 2004.

FIELD OF THE INVENTION

This invention relates to compounds which are useful as therapeuticagents. Among other potential uses, these compounds are believed to haveproperties which are characteristic of prostaglandins.

BACKGROUND OF THE INVENTION Description of Related Art

Ocular hypotensive agents are useful in the treatment of a number ofvarious ocular hypertensive conditions, such as post-surgical andpost-laser trabeculectomy ocular hypertensive episodes, glaucoma, and aspresurgical adjuncts.

Glaucoma is a disease of the eye characterized by increased intraocularpressure. On the basis of its etiology, glaucoma has been classified asprimary or secondary. For example, primary glaucoma in adults(congenital glaucoma) may be either open-angle or acute or chronicangle-closure. Secondary glaucoma results from pre-existing oculardiseases such as uveitis, intraocular tumor or an enlarged cataract.

The underlying causes of primary glaucoma are not yet known. Theincreased intraocular tension is due to the obstruction of aqueous humoroutflow. In chronic open-angle glaucoma, the anterior chamber and itsanatomic structures appear normal, but drainage of the aqueous humor isimpeded. In acute or chronic angle-closure glaucoma, the anteriorchamber is shallow, the filtration angle is narrowed, and the iris mayobstruct the trabecular meshwork at the entrance of the canal ofSchlemm. Dilation of the pupil may push the root of the iris forwardagainst the angle, and may produce pupilary block and thus precipitatean acute attack. Eyes with narrow anterior chamber angles arepredisposed to acute angle-closure glaucoma attacks of various degreesof severity.

Secondary glaucoma is caused by any interference with the flow ofaqueous humor from the posterior chamber into the anterior chamber andsubsequently, into the canal of Schlemm. Inflammatory disease of theanterior segment may prevent aqueous escape by causing completeposterior synechia in iris bombe, and may plug the drainage channel withexudates. Other common causes are intraocular tumors, enlargedcataracts, central retinal vein occlusion, trauma to the eye, operativeprocedures and intraocular hemorrhage.

Considering all types together, glaucoma occurs in about 2% of allpersons over the age of 40 and may be asymptotic for years beforeprogressing to rapid loss of vision. In cases where surgery is notindicated, topical β-adrenoreceptor antagonists have traditionally beenthe drugs of choice for treating glaucoma.

Certain eicosanoids and their derivatives have been reported to possessocular hypotensive activity, and have been recommended for use inglaucoma management. Eicosanoids and derivatives include numerousbiologically important compounds such as prostaglandins and theirderivatives. Prostaglandins can be described as derivatives ofprostanoic acid which have the following structural formula:

Various types of prostaglandins are known, depending on the structureand substituents carried on the alicyclic ring of the prostanoic acidskeleton. Further classification is based on the number of unsaturatedbonds in the side chain indicated by numerical subscripts after thegeneric type of prostaglandin [e.g. prostaglandin E₁ (PGE₁),prostaglandin E₂ (PGE₂)], and on the configuration of the substituentson the alicyclic ring indicated by α or β [e.g. prostaglandin F_(2α)(PGF_(2β))].

Prostaglandins were earlier regarded as potent ocular hypertensives,however, evidence accumulated in the last decade shows that someprostaglandins are highly effective ocular hypotensive agents, and areideally suited for the long-term medical management of glaucoma (see,for example, Bito, L. Z. Biological Protection with Prostaglandins,Cohen, M. M., ed., Boca Raton, Fla., CRC Press Inc., 1985, pp. 231-252;and Bito, L. Z., Applied Pharmacology in the Medical Treatment ofGlaucomas Drance, S. M. and Neufeld, A. H. eds., New York, Grune &Stratton, 1984, pp. 477-505. Such prostaglandins include PGF_(2α),PGF_(1α), PGE_(2,) and certain lipid-soluble esters, such as C₁ to C₂alkyl esters, e.g. 1-isopropyl ester, of such compounds.

Although the precise mechanism is not yet known experimental resultsindicate that the prostaglandin-induced reduction in intraocularpressure results from increased uveoscleral outflow [Nilsson et. al.,Invest. Ophthalmol. Vis. Sci. (suppl), 284 (1987)].

The isopropyl ester of PGF_(2α)has been shown to have significantlygreater hypotensive potency than the parent compound, presumably as aresult of its more effective penetration through the cornea. In 1987,this compound was described as “the most potent ocular hypotensive agentever reported” [see, for example, Bito, L. Z., Arch. Ophthalmol. 1051036 (1987), and Siebold et al., Prodrug 5 3 (1989)].

Whereas prostaglandins appear to be devoid of significant intraocularside effects, ocular surface (conjunctival) hyperemia and foreign-bodysensation have been consistently associated with the topical ocular useof such compounds, in particular PGF_(2α)and its prodrugs, e.g., its1-isopropyl ester, in humans. The clinical potentials of prostaglandinsin the management of conditions associated with increased ocularpressure, e.g. glaucoma are greatly limited by these side effects.

In a series of United States patents assigned to Allergan, Inc.prostaglandin esters with increased ocular hypotensive activityaccompanied with no or substantially reduced side-effects are disclosed.Some representative examples are U.S. Pat. No. 5,446,041, U.S. Pat. No.4,994,274, U.S. Pat. No. 5,028,624 and U.S. Pat. No. 5,034,413 all ofwhich are hereby expressly incorporated by reference.

U.S. Pat. No. 5,688,819, commonly assigned to Allergan, Inc., andincorporated herein by reference discloses compounds known asprostamides. Prostamides are distinguished from prostaglandins in thatthe oxygen which is bonded to carbonyl group is replaced by a nitrogenbearing substituent. Those skilled in the art will readily recognizethat this replacement significantly alters several electronic and stericproperties of an important structural feature in the biologicalmolecule. Significantly, it is commonly believed in the art thatresonance between the nitrogen lone pair and the carbonyl π-bond issignificantly greater than resonance between the carbonyl group and anoxygen lone pair in a carboxylic ester or a carboxylic acid. This beliefis supported by the well established experimental observation that thenitrogen atom in an amide is planar, as opposed to the pyramidalgeometry of an amine. Thus, the commonly accepted belief in the art isthat the nitrogen atom of an amine is sp³ hybridized, while nitrogenatom of an amide is sp² hybridized, with the bonded electrons occupyingthe sp² hybrid orbitals and the nonbonded electron pair occupying a porbital to allow for conjugation with the carbonyl π system. Bycontrast, the hybridization, bonding, and geometry of the electrons ofthe oxygen atom in water and alcohols are very similar to those ofcarboxylic acids or carboxylic esters.

The increased resonance between the nitrogen and the carbonyl group inthe amide confers several unique properties to the molecule. First, itis well known in the art that hydrolysis of amides is at least twoorders of magnitude slower than the hydrolysis of esters (see, forexample, Francis A. Carey, Organic Chemistry, New York: McGraw-Hill BookCompany, 1987, p. 779). Thus, hydrolysis of amides in vivo is slowed tosuch an extent that a prostamide cannot be considered to be a prodrug ofa prostaglandin. Second, the increased resonance significantly increasesthe barrier to rotation about the nitrogen-carbonyl sigma bond relativeto the analogous rotational barrier associated with esters andcarboxylic acids. Thus, a prostamide has a sterically significant,stable, rigid group replacing the oxygen atom of the prostaglandin. Thissignificant steric difference will have a significant effect in bindingto a number of receptor sites since geometry is important for manyreceptor sites. Since the carboxylic acid group of a prostaglandin is apolar, ionizable, group, with four potential hydrogen bond receivingelectron pairs, and in the case of the protonated acid, one potentialhydrogen bond donor, it is reasonable for a person of ordinary skill inthe art to believe that this functional group will be important to thebinding of the molecule to a number of receptors. It follows thatchanging the resonance properties, the hybridization of the bonding andnonbonding electrons, the geometry of the nitrogen atom, the number ofavailable hydrogen bonding sites, and the electronegativity of the ofthe nitrogen relative to oxygen, will confer significantly differentbiological properties to prostamides relative to prostaglandins.

Recently, it is becoming more commonly accepted in the art that amideshave distinct properties over carboxylic acids. For example, it has beenshown that anandamide, a common amide of arachidonic acid, hassignificant biological activity that arachidonic acid does not. Otherwork has also been done to show that amides have distinct activity ascompared to carboxylic acid, which has caused some in the field toclassify fatty acid amides as “a new family of biologically activelipids” (Bezuglov, et. al., “Synthesis and Biological Evaluation ofNovel Amides of Polyunsaturated Fatty Acids with Dopamine”, Bioorganic &Medicinal Chemistry Letters 11 (2001), 447-449).

It has been shown that prostamides have pronounced effects on smoothmuscle and are potent ocular hypotensive agents. Additionally,prostamides cause significantly lower ocular surface hyperemia thanprostaglandins. One prostamide exemplary of the these effects isbimatoprost, which is marketed by Allergan, Inc. under the trade nameLumigan®, which has the structure shown below.

Although prostamide compounds have activity which is distinct fromprostaglandins, they have many similar structural features. While notintending to be bound in any way by theory, it is believed that thestructural similarity arises because prostamides are biosynthesized fromN-arachidonyl ethanolamide whereas prostaglandins are biosynthesizedfrom the structurally related arachidonic acid. Thus, they have similarstructural traits, but play physiologically distinct roles due to theunique differences between the amide and the acid or ester functionalgroups highlighted previously. For example, it is believed that the twoclasses of compounds are active at distinct receptors. Thus, it isbelieved that the prostamide and prostaglandin receptors recognize asimilar geometry in terms of the basic ring and α- and ω- chainstructure, or analogs thereof, but selectively distinguish betweenprostaglandin and prostamide compounds based upon the nitrogen or oxygensubstitution at the carbonyl.

10-Hydroxyprostaglandin analogues, that is natural prostaglandin Ecompounds where the hydroxide is present on carbon 10 rather than carbon11, are known in several patent documents including U.S. Pat. No.4,171,375; U.S. Pat. No. 3,931,297; FR 2408567; DE 2752523, JP 53065854,DE 2701455, SE 7700257, DK 7700272, NL 7700272, JP 52087144, BE 850348,FR 2338244, FR 2162213, GB 1405301, and ES 409167.

Prostaglandin EP₄ selective agonists are believed to have severalmedical uses. For example, U.S. Pat. No. 6,552,067 B2 teaches the use ofprostaglandin EP4 selective agonists for the treatment of “methods oftreating conditions which present with low bone mass, particularlyosteoporosis, frailty, an osteoporotic fracture, a bone defect,childhood idiopathic bone loss, alveolar bone loss, mandibular boneloss, bone fracture, osteotomy, bone loss associated with periodontitis,or prosthetic ingrowth in a mammal”. U.S. Pat. No. 6,586,468 B 1 teachesthat prostaglandin EP4 selective agonists “are useful for theprophylaxis and/or treatment of immune diseases (autoimmune diseases(amyotrophic lateral sclerosis (ALS), multiple sclerosis, Sjoegren'ssyndrome, arthritis, rheumatoid arthritis, systemic lupus erythematosus,etc.), post-transplantation graft rejection, etc.), asthma, abnormalbone formation, neurocyte death, pulmopathy, hepatopathy, acutehepatitis, nephritis, renal insufficiency, hypertension, myocardialischemia, systemic inflammatory syndrome, pain induced by ambustion,sepsis, hemophagocytosis syndrome, macrophage activation syndrome,Still's diseases, Kawasaki diseases, burn, systemic granuloma,ulcerative colititis, Crohn's diseases, hypercytokinemia at dialysis,multiple organ failure, shock, etc. They are also connected withsleeping disorders and platelet coagulations, and therefore they arethought to be useful for these diseases.”

BRIEF DESCRIPTION OF THE INVENTION

A compound comprising

or a pharmaceutically acceptable salt or a prodrug thereof,whereinthe dashed line represents the presence or absence of a double bond;J is C═O or CHOH;A is —(CH₂)₆-, or cis —CH₂CH═CH—(CH₂)₃-, wherein 1 or 2 carbons may besubstituted with S or O;B is CO₂H, or CO₂R, CONR₂, CONHCH₂CH₂OH, CON(CH₂CH₂OH)₂, CH₂OR,P(O)(OR)₂, CONRSO₂R, SONR2, or

R is H, C₁₋₆ alkyl;D is —(CH₂)_(n)-, —X(CH₂)_(n), or —(CH₂)_(n)X-, wherein n is from 0 to 3and X is S or O;andE is an aromatic or heteroaromatic moiety having from 0 to 4substituents, said substituents each comprising from 1 to 6 non-hydrogenatoms is disclosed herein.

Also disclosed herein are methods of treating diseases or conditions,including glaucoma, elevated intraocular pressure, and diseases relatedto the activity of a prostaglandin EP₄ receptor. Compositions andmethods of manufacturing medicaments related thereto are also disclosed.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

Schemes 1 and 2 illustrate one method of preparing the compoundsdisclosed herein.

DETAILED DESCRIPTION OF THE INVENTION

Several of the carbon atoms on these compounds are chiral centers. Whilenot intending to limit the scope of the invention in any way, or bebound in any way by theory, it is believed that many compounds andpharmaceutically active salts or prodrugs thereof having thestereochemistry shown below are particularly useful.

However, it is also advantageous if one of the bonds has the indicatedstereochemistry, while the stereochemistry of other bond to chiralcenters may vary. Thus, while not intending to limit the scope of theinvention in any way, compounds comprising

and pharmaceutically acceptable salts and prodrugs thereof, areparticularly useful in the context disclosed herein.

A person of ordinary skill in the art understands the meaning of thestereochemistry associated with the hatched wedge/solid wedge structuralfeatures. For example, an introductory organic chemistry textbook(Francis A. Carey, Organic Chemistry, New York: McGraw-Hill Book Company1987, p. 63) states “a wedge indicates a bond coming from the plane ofthe paper to toward the viewer” and the hatched wedge, indicated as a“dashed line”, “represents a bond receding from the viewer.”

In relation to the identity of A disclosed in the chemical structurespresented herein, in the broadest sense, A is —(CH₂)₆-, or cis—CH₂CH═CH—(CH₂)₃-, wherein 1 or 2 carbons may be substituted with S orO. In other words, A may be —(CH₂)₆-, cis —CH₂CH═CH—(CH₂)₃-, or A may bea group which is related to one of these two moieties in that any carbonis substituted with S or O. For example, while not intending to limitthe scope of the invention in any way, S may be an S substituted moietysuch as one of the following or the like.

Alternatively, while not intending to limit the scope of the inventionin any way, S may be an O substituted moiety such as one of thefollowing or the like.

In other embodiments, A is —(CH₂)₆- or cis-CH₂CH═CH—(CH₂)₃- having noheteroatom substitution.

The term alkyl has the meaning generally understood by those skilled inthe art and refers to linear, branched, or cyclic alkyl moieties. A“C₁₋₆ alkyl” moiety has from 1 to 6 carbon atoms and includes, but isnot limited to, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl,iso-butyl, t-butyl, pentyl isomers, hexyl isomers, cyclopropyl,cyclobutyl, cyclopentyl, cyclohexyl, and combinations thereof havingfrom 1-6 carbon atoms, etc. In compounds where B is CO₂R, CONR₂, CH₂OR,P(O)(OR)₂, CONRSO₂R, SONR₂, compounds wherein R is methyl, ethyl, orisopropyl, are specifically contemplated herein.

In relation to the identity of D, D is —(CH₂)_(n)-, —X(CH₂)_(n), or—(CH₂)_(n)X-, wherein n is from 0 to 3 and X is S or O. In other words,while not intending to be limiting, D may be a bond, —CH₂-, —CH₂CH₂-,—CH₂CH₂CH₂-, S, O, —SCH₂-, —SCH₂CH₂-, —SCH₂CH₂CH₂-, —CH₂S-, —CH₂CH₂S-,—CH₂CH₂CH₂S-, —OCH₂-, —OCH₂CH₂-, —OCH₂CH₂CH₂-, —CH₂O-, —CH₂CH₂O-, or—CH₂CH₂CH₂O-. A person of ordinary skill in the art will understand thatn is required to be an integer.

In relation to E, E is an aromatic or heteroaromatic moiety having from0 to 4 substituents, said substituents each comprising from 1 to 6non-hydrogen atoms. In other words, E can be an aromatic moiety such asphenyl, napthyl, etc, or E can be a heteroaromatic moiety such asthienyl, pyridinyl, furyl, benzothienyl, etc. Alternatively, E can beone of these aromatic or heteroaromatic moieties, which is substitutedwith from 1 to 4 substituents. The substituents comprise from 1 to 6non-hydrogen atoms, in other words, there are from 1 to 6 atoms whichare not hydrogen, any number of hydrogen atoms required to form thecomplete substituent. For example, a methyl substituent has 1 carbonatom and 3 hydrogen atoms. Other example substituents include otherhydrocarbon moieties comprising from 1 to 6 carbon atoms including alkylsuch as ethyl, propyl, isopropyl, butyl and isomers thereof, pentyl andisomers thereof, hexyl and isomers thereof; cyclic and unsaturatedhydrocarbons having 1 to 6 carbon atoms; CO₂H and salts thereof; alkoxyup to C₅ such as methoxy, ethoxy, propoxy, isopropoxy, a butoxy isomer,or a pentoxy isomer; carboxylic acid esters; CN; NO₂; CF₃; F; Cl; Br; I;sulfonyl esters; SO₃H and salts thereof; and the like. Thesesubstituents may be in any reasonable position on the aromatic orheteroaromatic moiety. A person of ordinary skill in the art willunderstand that the number of substituents will be an integer.

In other words, while not intending to limit the scope of the inventionin any way E can be chlorophenyl, dichlorophenyl, trichlorophenyl,tetrachlorophenyl, fluorophenyl, difluorophenyl, trifluorophenyl,tetrafluorophenyl, (trifluoromethyl)phenyl, di(trifluoromethyl)phenyl,tri(trifluoromethyl)phenyl, tetra(trifluoromethyl)phenyl, methylphenyl,dimethylphenyl, trimethylphenyl, tetramethylphenyl, methoxyphenyl,dimethoxyphenyl, trimethoxyphenyl, tetramethoxyphenyl, cyanophenyl,dicyanophenyl, tricyanophenyl, tetracyanophenyl, or can have mixedsubstituents such as chlorofluorophenyl, chloromethylphenyl,chloromethoxyphenyl, chloroflouromethylphenyl, etc. Similarly, while notintending to be limiting, other aromatic moieties could bechloronapthyl, dichloronapthyl, trichloronapthyl, tetrachloronapthyl,fluoronapthyl, difluoronapthyl, trifluoronapthyl, tetrafluoronapthyl,(trifluoromethyl)napthyl, di(trifluoromethyl)napthyl,tri(trifluoromethyl)napthyl, tetra(trifluoromethyl)napthyl,methylnapthyl, dimethylnapthyl, trimethylnapthyl, tetramethylnapthyl,methoxynapthyl, dimethoxynapthyl, trimethoxynapthyl,tetramethoxynapthyl, cyanonapthyl, dicyanonapthyl, tricyanonapthyl,tetracyanonapthyl, or can have mixed substituents such aschlorofluoronapthyl, chloromethylnapthyl, chloromethoxynapthyl,chloroflouromethylnapthyl, etc. Heteroaromatic moieties, could include,but are not limited to chloropyridinyl, dichloropyridinyl,trichloropyridinyl, tetrachloropyridinyl, fluoropyridinyl,difluoropyridinyl, trifluoropyridinyl, tetrafluoropyridinyl,(trifluoromethyl)pyridinyl, di(trifluoromethyl)pyridinyl,tri(trifluoromethyl)pyridinyl, tetra(trifluoromethyl)pyridinyl,methylpyridinyl, dimethylpyridinyl, trimethylpyridinyl,tetramethylpyridinyl, methoxypyridinyl, dimethoxypyridinyl,trimethoxypyridinyl, tetramethoxypyridinyl, cyanopyridinyl,dicyanopyridinyl, tricyanopyridinyl, tetracyanopyridinyl, or can havemixed substituents such as chlorofluoropyridinyl, chloromethylpyridinyl,chloromethoxypyridinyl, chloroflouromethylpyridinyl, etc. Similarly,while not intending to be limiting, other heteroaromatic moieties couldbe chlorobenzothienyl, dichlorobenzothienyl, trichlorobenzothienyl,tetrachlorobenzothienyl, fluorobenzothienyl, difluorobenzothienyl,trifluorobenzothienyl, tetrafluorobenzothienyl,(trifluoromethyl)benzothienyl, di(trifluoromethyl)benzothienyl,tri(trifluoromethyl)benzothienyl, tetra(trifluoromethyl)benzothienyl,methylbenzothienyl, dimethylbenzothienyl, trimethylbenzothienyl,tetramethylbenzothienyl, methoxybenzothienyl, dimethoxybenzothienyl,trimethoxybenzothienyl, tetramethoxybenzothienyl, cyanobenzothienyl,dicyanobenzothienyl, tricyanobenzothienyl, tetracyanobenzothienyl, orcan have mixed substituents such as chlorofluorobenzothienyl,chloromethylbenzothienyl, chloromethoxybenzothienyl,chloroflouromethylbenzothienyl, etc.

In other embodiments E is an aromatic or heteroaromatic moiety havingfrom 0 to 2 substituents, wherein said aromatic moiety is selected fromthe group consisting of phenyl, thienyl, benzothienyl, and napthyl, andsaid substituents are selected from the group consisting of methyl,methoxy, chloro, and fluoro. In other words, E can be phenyl, thienyl,benzothienyl, and napthyl, or a mono- or disubstituted derivative ofphenyl, thienyl, benzothienyl, and napthyl, such as chlorophenyl,dichlorophenyl, chlorofluorophenyl, fluorophenyl, difluorophenyl,methylphenyl, dimethylphenyl, etc, chlorothienyl, dichlorothienyl,chlorofluorothienyl, fluorothienyl, difluorothienyl, methylthienyl,dimethylthienyl, etc, chlorobenzothienyl, dichlorobenzothienyl,chlorofluorobenzothienyl, fluorobenzothienyl, difluorobenzothienyl,methylbenzothienyl, dimethylbenzothienyl, etc, chloronaphthyl,dichloronaphthyl, chlorofluoronaphthyl, fluoronaphthyl,difluoronaphthyl, methylnaphthyl, dimethylnaphthyl, etc. Thesesubstituents may be in any reasonable position on the aromatic orheteroaromatic moiety. A person of ordinary skill in the art willunderstand that the number of substituents will be an integer.

In other embodiments, E is a moiety selected from the group consistingof phenyl, napthyl, and benzothienyl, or E is a monochloro derivative ofone of these moieties, i.e. chlorophenyl, chloronaphthyl, orchlorobenzothienyl. These substituents may be in any position on thearomatic or heteroaromatic moiety.

A “pharmaceutically acceptable salt” is any salt that retains theactivity of the parent compound and does not impart any additionaldeleterious or untoward effects on the subject to which it isadministered and in the context in which it is administered compared tothe parent compound.

Pharmaceutically acceptable salts of acidic functional groups may bederived from organic or inorganic bases. The salt may comprise a mono orpolyvalent ion. Of particular interest are the inorganic ions, lithium,sodium, potassium, calcium, and magnesium. Organic salts may be madewith amines, particularly ammonium salts such as mono-, di- and trialkylamines or ethanol amines. Salts may also be formed with caffeine,tromethamine and similar molecules. Hydrochloric acid or some otherpharmaceutically acceptable acid may form a salt with a compound thatincludes a basic group, such as an amine or a pyridine ring.

A “prodrug” is a compound which is converted to a therapeutically activecompound after administration, and the term should be interpreted asbroadly herein as is generally understood in the art. While notintending to limit the scope of the invention, conversion may occur byhydrolysis of an ester group or some other biologically labile group.Generally, but not necessarily, a prodrug is inactive or less activethan the therapeutically active compound to which it is converted.

Compounds comprising

or a pharmaceutically acceptable salt or a prodrug thereof, arespecifically contemplated herein.

Compounds comprising

or a pharmaceutically acceptable salt or a prodrug thereof, arespecifically contemplated herein.

Compounds comprising

or a pharmaceutically acceptable salt or a prodrug thereof, arespecifically contemplated herein.

Compounds comprising

or a pharmaceutically acceptable salt or a prodrug thereof, arespecifically contemplated herein.

Other embodiments comprise

or a pharmaceutically acceptable salt or a prodrug thereof, wherein G isCH₂, O, or S.

Other embodiments comprise

or a pharmaceutically acceptable salt or a prodrug thereof, wherein G isCH₂, O, or S.

Other compounds comprise

or a pharmceutically acceptable salt or a prodrug thereof, wherein G isCH₂, O, or S.

Other compounds comprise

or a pharmaceutically acceptable salt or a prodrug thereof, wherein G isCH₂, O, or S.

Other embodiments comprise In these embodiments, B and E have themeanings previously described.

Another embodiment comprises

or a pharmaceutically acceptable salt or a prodrug thereof.

Another embodiment comprises

or a pharmaceutically acceptable salt or a prodrug thereof.

Another embodiment comprises

or a pharmaceutically acceptable salt or a prodrug thereof, wherein R²is an alkyl moiety having from 1 to 6 carbons. Thus, R² may be methyl,ethyl, propyl, isopropyl, butyl or an isomer thereof, pentyl or anisomer thereof, or hexyl or an isomer thereof.

Another embodiment comprises one the following compounds:(Z)-7-{(1R,5R)-5-[(E)-5-(3-Chloro-benzo[b]thiophen-2-yl)-3-hydroxy-pent-1-enyl]-3-hydroxy-2-oxo-cyclopentyl}-hept-5-enoicacid methyl ester (high and low Rf methyl esters 8H, 8L), and(Z)-7-{(1R,5R)-5-[(E)-5-(3-Chloro-benzo[b]thiophen-2-yl)-3-hydroxy-pent-1-enyl]-3-hydroxy-2-oxo-cyclopentyl}-hept-5-enoicacid (high and low Rf acids,9H, 9L).

The compounds of disclosed herein are useful for the prevention ortreatment of glaucoma or ocular hypertension in mammals, or for themanufacture of a medicament for the treatment of glaucoma or ocularhypertension.

The compounds disclosed herein are also useful as selective agonists ofprostaglandin EP₄ receptors. As such they are useful for the treatmentof certain diseases or conditions, particularly those which are relatedto activity of a prostaglandin EP₄ receptor. While not intending tolimit the scope of the invention in any way, or be bound in any way bytheory, it is commonly believed in the art that prostaglandin EP₄receptor activity is related to the following diseases or conditions,and as such, these diseases or conditions may be prevented or treated byprostaglandin EP₄ receptor agonists: asthma, dysmenorrhea, osteoporosis,bone disorders, constipation, renal disorders, sexual dysfunction,baldness, acute hepatitis, bronchitis, burn, chronic obstructiverespiratory diseases, Crohn's disease, digestive ulcer, hemophagoussyndrome, hepatopathy, hypercytokinemia at dialysis, hypertension,immunological diseases, inflammatory conditions, Kawasaki disease, liverinjury, macrophage activation syndrome, myocardial ischemia, nephritis,nerve cell death, premature birth, pulmonary emphysema, pulmonaryfibrosis, pulmonary injury, renal failure, sepsis, shock, sleepdisorder, Still disease, stomatitis, systemic granuloma, systemicinflammatory syndrome, thrombosis and stroke, ulcerative colitis, acutemyocardial infarction, vascular thrombosis, hypertension, pulmonaryhypertension, ischemic heart disease, congestive heart failure, andangina pectoris.

Those skilled in the art will readily understand that for administrationor the manufacture of medicaments the compounds disclosed herein can beadmixed with pharmaceutically acceptable excipients which per se arewell known in the art. Specifically, a drug to be administeredsystemically, it may be confected as a powder, pill, tablet or the like,or as a solution, emulsion, suspension, aerosol, syrup or elixirsuitable for oral or parenteral administration or inhalation.

For solid dosage forms or medicaments, non-toxic solid carriers include,but are not limited to, pharmaceutical grades of mannitol, lactose,starch, magnesium stearate, sodium saccharin, the polyalkylene glycols,talcum, cellulose, glucose, sucrose and magnesium carbonate. The soliddosage forms may be uncoated or they may be coated by known techniquesto delay disintegration and absorption in the gastrointestinal tract andthereby provide a sustained action over a longer period. For example, atime delay material such as glyceryl monostearate or glyceryl distcaratemay be employed. They may also be coated by the technique described inthe U.S. Pat. Nos. 4,256,108; 4,166,452; and 4,265,874 to form osmotictherapeutic tablets for control release. Liquid pharmaceuticallyadministrable dosage forms can, for example, comprise a solution orsuspension of one or more of the presently useful compounds and optionalpharmaceutical adjutants in a carrier, such as for example, water,saline, aqueous dextrose, glycerol, ethanol and the like, to therebyform a solution or suspension. If desired, the pharmaceuticalcomposition to be administered may also contain minor amounts ofnontoxic auxiliary substances such as wetting or emulsifying agents, pHbuffering agents and the like. Typical examples of such auxiliary agentsare sodium acetate, sorbitan monolaurate, triethanolamine, sodiumacetate, triethanolamine oleate, etc. Actual methods of preparing suchdosage forms are known, or will be apparent, to those skilled in thisart; for example, see Remington's Pharmaceutical Sciences, MackPublishing Company, Easton, Pa., 16th Edition, 1980. The composition ofthe formulation to be administered, in any event, contains a quantity ofone or more of the presently useful compounds in an amount effective toprovide the desired therapeutic effect.

Parenteral administration is generally characterized by injection,either subcutaneously, intramuscularly or intravenously. Injectables canbe prepared in conventional forms, either as liquid solutions orsuspensions, solid forms suitable for solution or suspension in liquidprior to injection, or as emulsions. Suitable excipients are, forexample, water, saline, dextrose, glycerol, ethanol and the like. Inaddition, if desired, the injectable pharmaceutical compositions to beadministered may also contain minor amounts of non-toxic auxiliarysubstances such as wetting or emulsifying agents, pH buffering agentsand the like.

The amount of the presently useful compound or compounds administeredis, of course, dependent on the therapeutic effect or effects desired,on the specific mammal being treated, on the severity and nature of themammal's condition, on the manner of administration, on the potency andpharmacodynamics of the particular compound or compounds employed, andon the judgment of the prescribing physician. The therapeuticallyeffective dosage of the presently useful compound or compounds ispreferably in the range of about 0.5 or about 1 to about 100 mg/kg/day.

For ophthalmic application, solutions or medicaments are often preparedusing a physiological saline solution as a major vehicle. Ophthalmicsolutions should preferably be maintained at a comfortable pH with anappropriate buffer system. The formulations may also containconventional, pharmaceutically acceptable preservatives, stabilizers andsurfactants.

Preservatives that may be used in the pharmaceutical compositions of thepresent invention include, but are not limited to, benzalkoniumchloride, chlorobutanol, thimerosal, phenylmercuric acetate andphenylmercuric nitrate. A useful surfactant is, for example, Tween 80.Likewise, various useful vehicles may be used in the ophthalmicpreparations of the present invention. These vehicles include, but arenot limited to, polyvinyl alcohol, povidone, hydroxypropyl methylcellulose, poloxamers, carboxymethyl cellulose, hydroxyethyl celluloseand purified water.

Tonicity adjustors may be added as needed or convenient. They include,but are not limited to, salts, particularly sodium chloride, potassiumchloride, mannitol and glycerin, or any other suitable ophthalmicallyacceptable tonicity adjustor.

Various buffers and means for adjusting pH may be used so long as theresulting preparation is ophthalmically acceptable. Accordingly, buffersinclude acetate buffers, citrate buffers, phosphate buffers and boratebuffers. Acids or bases may be used to adjust the pH of theseformulations as needed.

In a similar vein, an ophthalmically acceptable antioxidant for use inthe present invention includes, but is not limited to, sodiummetabisulfite, sodium thiosulfate, acetylcysteine, butylatedhydroxyanisole and butylated hydroxytoluene.

Other excipient components which may be included in the ophthalmicpreparations are chelating agents. A useful chelating agent is edetatedisodium, although other chelating agents may also be used in place orin conjunction with it.

The ingredients are usually used in the following amounts: IngredientAmount (% w/v) active ingredient about 0.001-5 preservative 0-0.10vehicle 0-40 tonicity adjustor 1-10 buffer 0.01-10 pH adjustor q.s. pH4.5-7.5 antioxidant as needed surfactant as needed purified water asneeded to make 100%

For topical use, creams, ointments, gels, solutions or suspensions,etc., containing the compound disclosed herein are employed. Topicalformulations may generally be comprised of a pharmaceutical carrier,cosolvent, emulsifier, penetration enhancer, preservative system, andemollient.

The actual dose of the active compounds of the present invention dependson the specific compound, and on the condition to be treated; theselection of the appropriate dose is well within the knowledge of theskilled artisan.

EXAMPLE 1(Z)-7-{(1R,2R,3R)-3-(tert-Butyl-dimethyl-silanyloxy)-2-[(E)-3-(tert-butyl-dimethyl-silanyloxy)-5-(3-chloro-benzo[b]thiophen-2-yl)-pent-1-enyl]-5-oxo-cyclopentyl}-hept-5-enoicacid methyl ester (3)

Iodide 1 was prepared according to the method described in U.S. patentapplication Ser. No. 365,369, filed Feb. 11, 2003, incorporated hereinby reference. A −78° C solution of iodide 1 (scheme 1, 2.305 g, 4.6mmol) in THF (10 mL) was treated dropwise with t-butyllithium (5.9 mL,10.0 mmol, 1.7 M/pentane). After stirring for 30 minutes, the redmixture was treated with lithium 2-thienylcyanocuprate (18.4 mL, 4.6mmol, 0.25 M/THF, Aldrich). The resulting brown mixture was stirred inan ice bath for 10 minutes and then was cooled back down to −78° C. Atthis time, a solution of enone 2 (1.63 g, 4.6 mmol) in THF (5.0 mL) wasadded dropwise by cannula and the resulting mixture stirred for 30minutes at −78° C, 30 minutes at 0° C and then 30 min. at roomtemperature.

The reaction was quenched by addition of a solution of 10 mLconcentrated NH₄OH in 90 mL saturated NH₄Cl. The resulting mixture wasstirred for 15 min. and was then extracted with ethyl acetate (3×100mL). The combined ethyl acetate solution was dried (MgSO₄), filtered,and evaporated. Purification by flash chromatography on silica gel (10%ethyl acetate/hexanes) provided the title ketone 3 (1.781 g, 2.5 mmol,54%).

(Z)-7-{(1R,2S)-2-[(E)-3-(tert-Butyl-dimethyl-silanyloxy)-5-(3-chloro-benzo[b]thiophen-2-yl)-pent-1-enyl]-5-oxo-cyclopent-3-enyl}-hept-5-enoicacid methyl ester (4)

A solution of ketone 3 (1.781 g, 2.5 mmol,) in acetic acid (24 mL)/H₂O(12 mL)/THF (12 mL) was heated at 70° C (bath temperature) for 16 h. Thesolution was allowed to cool to room temperature and then was pouredinto 750 mL saturated NaHCO₃ solution. The mixture was extracted withethyl acetate (4×200 mL) and the combined ethyl acetate solution wasdried (Na₂SO₄), filtered and evaporated. Purification by flashchromatography on silica gel (50% ethyl acetate/hexanes) gave 0.686 g(1.5 mmol, 60%) of the deprotected version of alcohol. 4.

A solution of the deprotected alcohol in dichloromethane (8 mL) wastreated with 2,6-lutidine (0.20 mL, 1.7 mmol) and TBSOTf (0.37 mL, 1.6mmol). After 1 h, saturated NaHCO₃ was added and the resulting mixtureextracted with dichloromethane (3×25 mL). The combined dichloromethanesolution was washed with 1 M HCl (50 mL) and brine (50 mL) and then wasdried (Na₂SO₄), filtered and evaporated. Purification by flashchromatography on silica gel (10% ethyl acetate/hexanes) gave the titleenone 4 (706 mg, 1.2 mmol, 83%).

(Z)-7-{(1R,2R)-2-[(E)-3-(tert-Butyl-dimethyl-silanyloxy)-5-(3-chloro-benzo[b]thiophen-2-yl)-pent-1-enyl]-5-oxo-cyclopentyl}-hept-5-enoicacid methyl ester (5)

A solution of enone 4 (145 mg, 0.25 mmol) in toluene (4 mL) was added toa −45° C mixture of [Ph₃PCuH]₆ in toluene (4 mL), rinsing with 0.5 mLtoluene. The mixture was allowed to stir for 1 h and then was allowed towarm to room temperature. After 19 h at room temperature, the reactionwas quenched by addition of 15 mL saturated NH₄Cl solution. Theresulting mixture was extracted with ethyl acetate (3×15 mL) and thecombined ethyl acetate solution was dried (Na₂SO₄), filtered andevaporated. Purification by flash chromatography on silica gel (7.5%ethyl acetate/hexanes to 12.5%) gave ketone 5 (111 mg, 0.19 mmol, 76%).

(Z)-7-{(1R,5R)-5-[(E)-3-(tert-Butyl-dimethyl-silanyloxy)-5-(3-chloro-benzo[b]thiophen-2-yl)-pent-1-enyl]-2-trimethylsilanyloxy-cyclopent-2-enyl}-hept-5-enoicacid methyl ester (6, scheme 2)

A solution of ketone 5 (59 mg, 0.10 mmol) in THF (2 mL) was added to a−78° C solution of LDA (75 μL, 0.12 mmol, 1.6 M/cyclohexane) in THF (0.2mL). After 15 minutes, a solution of TMSCl (0.16 mL, 1.3 mmol) andtriethylamine (0.25 mL, 1.8 mL) in 4.4 mL THF was added by cannula.After 5 min. at −78° C, the reaction was allowed to warm to roomtemperature. The mixture was stirred for 20 min., was poured into 6 mLhexanes and then was filtered through celite, rinsing with 50% ethylacetate/hexanes. The filtrate was evaporated, taken into dichloromethaneand filtered through glass wool. Evaporation of the filtrate gave thecrude enol silane (32 mg, 0.047 mmol) which was used directly in thenext step. Dimethyldioxirane (prepared according to Adam et.al. J. Org.Chem. 1987, 52, 2800). NaHCO₃ (12 g, 143 mmol) was added to a solutionof acetone (11 mL, 150 mmol) in H₂O (20 mL). The flask was equipped witha short path distillation apparatus and a 50 mL receiving flask (cooledto −78° C). Oxone (25 g, 41 mmol) was added in one portion and a 180torr vacuum was applied. After 15 min., gas evolution had slowedconsiderably with ca. 10 mL of ca. 0.1 M dimethyldioxirane solutionbeing collected in the receiving flask. The solution was used directlyin the next step.

(Z)-7-{(1R,5R)-5-[(E)-3-(tert-Butyl-dimethyl-silanyloxy)-5-(3-chloro-benzo[b]thiophen-2-yl)-pent-1-enyl]-3-hydroxy-2-oxo-cyclopentyl}-hept-5-enoicacid methyl ester (7)

A −78° C solution of the crude enol silane (from above) was treated withdimethyldioxirane solution (1.2 mL, ca. 0. 1 M/acetone, prepared above).After 20 min., 10 mL saturated NaHSO₃ solution was added and thereaction allowed to warm to room temperature. Attempted extraction ofthe mixture with 15 mL dichloromethane resulted in an emulsion; howeveraddition of 15 mL ethyl acetate allowed for facile layer separation. Theaqueous layer was further extracted with ethyl acetate (2×15 mL) and thecombined ethyl acetate solution was dried (Na₂SO₄), filtered andevaporated.

The residue was dissolved in 5 mL 5:1 THF/H₂O and pyridiniump-toluenesulfonate (PPTs, 6 mg, 0.02 mmol) was added. After 20 min. morePPTs (14 mg, 0.05 mmol) was added. After another 20 min., 10 mLsaturated NaHCO₃ solution was added and the mixture was extracted withethyl acetate (1×50 mL, 2×25 mL). The combined ethyl acetate solutionwas dried (Na₂SO₄), filtered and evaporated. Purification by flashchromatography on silica gel (30% ethyl acetate/hexanes) gave hydroxylketone 7 (9 mg, 0.015 mmol, 32% from 6).

(Z)-7-{(1R,5R)-5-[(E)-5-(3-Chloro-benzo[b]thiophen-2-yl)-3-hydroxy-pent-1-enyl]-3-hydroxy-2-oxo-cyclopentyl}-hept-5-enoicacid methyl ester 8

An acetonitrile (0.35 mL) solution of 7 (9 mg, 0.015 mmol) was treatedwith HF-pyridine (0.07 mL). The solution was allowed to stir for 2 h andthen 20 mL of saturated NaHCO₃ solution was added. The mixture wasextracted with dichloromethane (3×15 mL) and the combineddichloromethane solution dried (Na₂SO₄), filtered and evaporated.Purification by preparative thin layer chromatography (50% ethylacetate/hexanes) gave two diastereomers of diol 8 (2 mg each, 0.004 mmoleach, 27% for each).

(Z)-7-{(1R,5R)-5-[(E)-5-(3-Chloro-benzo[b]thiophen-2-yl)-3-hydroxy-pent-1-enyl]-3-hydroxy-2-oxo-cyclopentyl}-hept-5-enoicacid 9 (high Rf diastereomer)

A mixture of 8 (2 mg, 0.004 mmol) and rabbit liver esterase (3 mg) in pH7.2 phosphate buffer (0.5 mL) and acetonitrile (0.05 mL) were stirredovernight. The volatiles were co-evaporated with acetonitrile (2×25 mL)and the residue was purified by flash chromatography on silica gel (5%methanol/dichloromethane) to give acid 9 (1 mg, 0.002 mmol, 50%). 300MHz ¹H NMR (CDCl3, ppm) δ7.73 (2 H, d, J=8.4 Hz) 7.5-7.3 (2 H, m)5.8-5.3 (4 H, m) 4.3-4.1 (2 H, overlapping m) 3.1-3.0 (2 H, m) 2.7-1.2(16 H, overlapping m).

The more polar diastereomer of 8 was hydrolyzed as above to give 9 (1mg, 0.002 mmol, 50%). 300 MHz IH NMR (CDC13, ppm) δ7.74 (2 H, d, J=7.9Hz) 7.5-7.3 (2 H, m) 5.7-5.4 (4 H, m) 4.3-4.1 (2 H, overlapping m)3.1-3.0 (2 H, m) 2.7-1.2 (16 H, overlapping m).

EXAMPLE 2

The biological activity of the compounds 1H and 1L, prepared asdescribed in Example 1 was tested using the following procedures.

Radioligand Binding

Cells Stably Expressing EP₁, EP₂, EP₄ and FP Receptors

HEK-293 cells stably expressing the human or feline FP receptor, or EP₁,EP₂, or EP₄ receptors were washed with TME buffer, scraped from thebottom of the flasks, and homogenized for 30 sec using a Brinkman PT10/35 polytron. TME buffer was added to achieve a final 40 ml volume inthe centrifuge tubes (the composition of TME is 100 mM TRIS base, 20 mMMgCl₂, 2M EDTA; 10N HCl is added to achieve a pH of 7.4).

The cell homogenate was centrifuged at 19000 r.p.m. for 20 min at 4° Cusing a Beckman Ti-60 rotor. The resultant pellet was resuspended in TMEbuffer to give a final 1 mg/ml protein concentration, as determined byBiorad assay. Radioligand binding competition assays vs. [³H-]17 -phenylPGF_(2α) (5 nM) were performed in a 100 μl volume for 60 min. Bindingreactions were started by adding plasma membrane fraction. The reactionwas terminated by the addition of 4 ml ice-cold TRIS-HCl buffer andrapid filtration through glass fiber GF/B filters using a Brandel cellharvester. The filters were washed 3 times with ice-cold buffer and ovendried for one hour.

[³H-] PGE₂ (specific activity 180 Ci mmol) was used as the radioligandfor EP receptors. [³H] 17-phenyl PGF_(2α) was employed for FP receptorbinding studies. Binding studies employing EP₁, EP₂, EP₄ and FPreceptors were performed in duplicate in at least three separateexperiments. A 200 μl assay volume was used. Incubations were for 60 minat 25° C and were terminated by the addition of 4 ml of ice-cold 50 mMTRIS-HCl, followed by rapid filtration through Whatman GF/B filters andthree additional 4 ml washes in a cell harvester (Brandel). Competitionstudies were performed using a final concentration of 5 nM [³H]-PGE₂, or5 nM [³H] 17-phenyl PGF_(2α) and non-specific binding determined with10⁻⁵ M of unlabeled PGE₂, or 17-phenyl PGF_(2α), according to receptorsubtype studied.

Methods for Flipr™ Studies

(a) Cell Culture

HEK-293(EBNA) cells, stably expressing one type or subtype ofrecombinant human prostaglandin receptors (prostaglandin receptorsexpressed: hDP/Gqs5; hEP₁; hEP₂/Gqs5; hEP_(3A)/Gqi5; hEP₄/Gqs5; hFP;hIP; hTP), were cultured in 100 mm culture dishes in high-glucose DMEMmedium containing 10% fetal bovine serum, 2 mM 1-glutamine, 250 μg/mlgeneticin (G418) and 200 μg/ml hygromycin B as selection markers, and100 units/ml penicillin G, 100 μg/ml streptomycin and 0.25 μg/mlamphotericin B.

(b) Calcium Signal Studies on the Flipr™

Cells were seeded at a density of 5×10⁴ cells per well in Biocoat®Poly-D-lysine-coated black-wall, clear-bottom 96-well plates(Becton-Dickinson) and allowed to attach overnight in an incubator at37° C. Cells were then washed two times with HBSS-HEPES buffer (HanksBalanced Salt Solution without bicarbonate and phenol red, 20 mM HEPES,pH 7.4) using a Denley Cellwash plate washer (Labsystems). After 45minutes of dye-loading in the dark, using the calcium-sensitive dyeFluo-4 AM at a final concentration of 2 μM, plates were washed fourtimes with HBSS-HEPES buffer to remove excess dye leaving 100 μl in eachwell. Plates were re-equilibrated to 37° C for a few minutes.

Cells were excited with an Argon laser at 488 nm, and emission wasmeasured through a 510-570 nm bandwidth emission filter (FLIPR™,Molecular Devices, Sunnyvale, Calif.). Drug solution was added in a 50μl volume to each well to give the desired final concentration. The peakincrease in fluorescence intensity was recorded for each well. On eachplate, four wells each served as negative (HBSS-HEPES buffer) andpositive controls (standard agonists: BW245C (hDP); PGE₂ (hEP₁;hEP₂/Gqs5; hEP_(3A)/Gqi5; hEP₄/Gqs5); PGF_(2α)(hFP); carbacyclin (hDP);U-46619 (hTP), depending on receptor). The peak fluorescence change ineach drug-containing well was then expressed relative to the controls.

Compounds were tested in a high-throughput (HTS) orconcentration-response (CoRe) format. In the HTS format, forty-fourcompounds per plate were examined in duplicates at a concentration of10⁻⁵ M. To generate concentration-response curves, four compounds perplate were tested in duplicates in a concentration range between 10⁻⁵and 10⁻¹¹ M. The duplicate values were averaged. In either, HTS or CoReformat each compound was tested on at least 3 separate plates usingcells from different passages to give an n≧3.

BINDING (nm) FUNCTIONAL (nm) COMPOUND HEP2 HEP3D HEP4 HFP HEP1 HEP2HEP3A HEP4 HTP HIP HDP 9H NA >10K 170 NA NA NA NA 53 NA NA NA 9L NA 8700200 NA NA NA NA 78 >10K NA NA

The results of the binding and activity studies presented in the tabledemonstrate that the compounds disclosed herein are selectiveprostaglandin EP₄ agonists, and are thus useful for the treatment ofglaucoma, ocular hypertension, the other diseases or conditionsdisclosed herein. Further, while not intending to limit the scope of theinvention in any way, or be bound in any way by theory, the 10-hydroxysubstitution of the compounds disclosed herein are believed to provideadditional stability relative to the analogous prostaglandin E compoundswhich have similar biological activity, and thus confer additionaladvantages.

The foregoing description details specific methods and compositions thatcan be employed to practice the present invention, and represents thebest mode contemplated. However, it is apparent for one of ordinaryskill in the art that further compounds with the desired pharmacologicalproperties can be prepared in an analogous manner, and that thedisclosed compounds can also be obtained from different startingcompounds via different chemical reactions. Similarly, differentpharmaceutical compositions may be prepared and used with substantiallythe same result. Thus, however detailed the foregoing may appear intext, it should not be construed as limiting the overall scope hereof;rather, the ambit of the present invention is to be governed only by thelawful construction of the appended claims.

1. A method comprising administering an effective amount of a compoundto a mammal for the treatment of a disease or condition related toactivity of a prostaglandin EP₄ receptor, said compound comprising

or a pharmaceutically acceptable salt or a prodrug thereof, wherein thedashed line represents the presence or absence of a bond; A is —(CH₂)₆-,or cis —CH₂CH═CH—(CH₂)₃-, wherein 1 or 2 carbons may be substituted withS or O; B is CO₂H, or CO₂R, CONR₂, CONHCH₂CH₂OH, CON(CH₂CH₂OH)₂, CH₂OR,P(O)(OR)₂, CONRSO₂R, SONR₂, or

R is H, C₁₋₆ alkyl; D is —(CH₂)_(n)-, —X(CH₂)_(n), or —(CH₂)_(n)X-,wherein n is from 0 to 3 and X is S or O; and E is an aromatic orheteroaromatic moiety having from 0 to 4 substituents, said substituentseach comprising from 1 to 6 non-hydrogen atoms.
 2. The method of claim 1wherein said disease or condition is selected from the group consistingof asthma, dysmenorrhea, osteoporosis, bone disorders, constipation,renal disorders, sexual dysfunction, baldness, acute hepatitis,bronchitis, burn, chronic obstructive respiratory diseases, Crohn'sdisease, digestive ulcer, hemophagous syndrome, hepatopathy,hypercytokinemia at dialysis, hypertension, immunological diseases,inflammatory conditions, Kawasaki disease, liver injury, macrophageactivation syndrome, myocardial ischemia, nephritis, nerve cell death,premature birth, pulmonary emphysema, pulmonary fibrosis, pulmonaryinjury, renal failure, sepsis, shock, sleep disorder, Still disease,stomatitis , systemic granuloma, systemic inflammatory syndrome,thrombosis and stroke, ulcerative colitis, acute myocardial infarction,vascular thrombosis, hypertension, pulmonary hypertension, ischemicheart disease, congestive heart failure, and angina pectoris.
 3. Themethod of claim 1 wherein A is —(CH₂)₆- or cis-CH₂CH═CH—(CH₂)₃- havingno heteroatom substitution.
 4. The method of claim 3, wherein saidcompound has the formula

or a pharmaceutically acceptable salt or a prodrug thereof.
 5. Themethod of claim 3, wherein said compound has the formula

or a pharmaceutically acceptable salt or a prodrug thereof, to a mammalsuffering from a disease or condition, wherein R² is an alkyl moietyhaving from 1 to 6 carbons, and said disease or condition is selectedfrom the group consisting of asthma, dysmenorrhea, osteoporosis, bonedisorders, constipation, renal disorders, sexual dysfunction, baldness,acute hepatitis, bronchitis, burn, chronic obstructive respiratorydiseases, Crohn's disease, digestive ulcer, hemophagous syndrome,hepatopathy, hypercytokinemia at dialysis, hypertension, immunologicaldiseases, inflammatory conditions, Kawasaki disease, liver injury,macrophage activation syndrome, myocardial ischemia, nephritis, nervecell death, premature birth, pulmonary emphysema, pulmonary fibrosis,pulmonary injury, renal failure, sepsis, shock, sleep disorder, Stilldisease, stomatitis, systemic granuloma, systemic inflammatory syndrome,thrombosis and stroke, ulcerative colitis, acute myocardial infarction,vascular thrombosis, hypertension, pulmonary hypertension, ischemicheart disease, congestive heart failure, and angina pectoris.